title: Experimental sleep curtailment causes wake-dependent increases in 24-h energy expenditure as measured by whole-room indirect calorimetry.
abstract: BACKGROUND
  Epidemiologic evidence has shown a link between short sleep and obesity. Clinical studies suggest a role of increased energy intake in this relation, whereas the contributions of energy expenditure (EE) and substrate utilization are less clearly defined.
  
  
  OBJECTIVE
  Our aim was to investigate the effects of sleep curtailment on 24-h EE and respiratory quotient (RQ) by using whole-room indirect calorimetry under fixed-meal conditions.
  
  
  METHODS
  Ten females aged 22-43 y with a BMI (in kg/m²) of 23.4-27.5 completed a randomized, crossover study. Participants were studied under short- (4 h/night) and habitual- (8 h/night) sleep conditions for 3 d, with a 4-wk washout period between visits. Standardized weight-maintenance meals were served at 0800, 1200, and 1900 with a snack at 1600. Measures included EE and RQ during the sleep episode on day 2 and continuously over 23 h on day 3.
  
  
  RESULTS
  Short compared with habitual sleep resulted in significantly higher (± SEM) 24-h EE (1914.0 ± 62.4 compared with 1822.1 ± 43.8 kcal; P = 0.012). EE during the scheduled sleep episode (0100-0500 and 2300-0700 in short- and habitual-sleep conditions, respectively) and across the waking episode (0800-2300) were unaffected by sleep restriction. RQ was unaffected by sleep restriction.
  
  
  CONCLUSIONS
  Short compared with habitual sleep is associated with an increased 24-h EE of ~92 kcal (~5%)--lower than the increased energy intake observed in prior sleep-curtailment studies. This finding supports the hypothesis that short sleep may predispose to weight gain as a result of an increase in energy intake that is beyond the modest energy costs associated with prolonged nocturnal wakefulness.
authors.affiliation: New York Obesity Nutrition Research Center, St Luke's-Roosevelt Hospital, New York, NY.
authors.forename: Ari
authors.initials: A
authors.lastname: Shechter
authors.forename: Russell
authors.initials: R
authors.lastname: Rising
authors.forename: Jeanine B
authors.initials: JB
authors.lastname: Albu
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: St-Onge
mesh_terms: D000328:Adult; D015992:Body Mass Index; D002153:Calorimetry, Indirect; D002940:Circadian Rhythm; D018592:Cross-Over Studies; D002149:Energy Intake; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D009043:Motor Activity; D050177:Overweight / Q000209:etiology / Q000378:metabolism*; D010101:Oxygen Consumption; D015203:Reproducibility of Results; D012892:Sleep Deprivation / Q000378:metabolism* / Q000503:physiopathology; D015854:Up-Regulation; D015430:Weight Gain; D055815:Young Adult